On Sun, Sep 25, 2022 at 05:28:29PM +0200, Mark Kettenis wrote: > > From: Daniel Pocock <dan...@pocock.pro> > > Date: Tue, 20 Sep 2022 11:45:50 +0200 > > > > After the feedback about amdgpu being unsupported on the big endian > > OpenBSD build, I decided to try a radeondrm supported card, the Radeon > > R9 290X ASUS DirectCU II 4GB. > > I fear that card is too new and doesn't work on big-endian platforms > either. Hawaii is GCN 2, but even GCN 1 cards (Oland) don't work > properly on big-endian machines. I don't really know at what hardware > generation big-endian support was abandoned by AMD/Linux. Maybe jsg@ > knows.
There are references to the previous generation (Northern Islands) working on big-endian platforms. https://lists.freedesktop.org/archives/xorg-announce/2011-March/001628.html "kms: evergreen/ni big endian accel support" Codenames are described in https://www.x.org/wiki/RadeonFeature/ https://lists.freedesktop.org/archives/amd-gfx/2018-June/023022.html "AFAIK all GPUs supported by amdgpu simply don't have these byte swapping capabilities anymore" Use of RDNA cards (which have DCN display blocks) is also limited to a small number of architectures as floating-point is used. Gated by CONFIG_DRM_AMD_DC_DCN. The low end of radeon cards has also moved from PCIe 3.0 x8 electrical on GCN parts to PCIe 4.0 x4 on RDNA2 parts. So a GCN part may even be preferred on amd64 machines with PCIe <= 3.0.
